Pediatric Cardiology
Domain focus
Pediatric cardiology tests recognition of congenital heart disease, murmur triage, cyanosis, heart failure, and ECG red flags.
Core rules
- Cyanotic newborn: obtain pre- and post-ductal SpO2, perform a hyperoxia test if stable; PaO2 <100 mmHg on 100% oxygen suggests cyanotic congenital heart disease.
- Ductal-dependent lesions (e.g., pulmonary atresia, critical coarctation, interrupted aortic arch, transposition) may decompensate as the ductus closes; start prostaglandin E1 and involve cardiology.
- Innocent murmurs are soft, systolic, grade ≤2, without clicks, with normal S2 and no symptoms; they vary with position.
- Newborn pulse-oximetry screening uses pre- and post-ductal measurements; a failed screen requires prompt echocardiography.
Worked example
A 2-week-old presents with poor feeding, tachypnea, and weak femoral pulses. Right-arm BP is 96/60 and left-leg BP is 70/40. Reasoning: upper-limb hypertension with lower-limb hypotension and weak femoral pulses suggests coarctation of the aorta. Start PGE1 if there is shock or ductal dependence, obtain echocardiography, and avoid aggressive diuresis before assessing perfusion.
Traps
- Attributing a pathologic murmur to “normal newborn flow” without checking pulses, BP, and oxygen saturation.
- Missing coarctation because the infant has a normal oxygen saturation.
- Using the hyperoxia test in an unstable infant instead of treating shock and calling cardiology.